A short entry.
This page contains quite a lot if internal informations as the FX-603P including useful PEEK and POKE command.
Sadly it is hosted on a "dodgy" server which most malware and spam filter will block. So here the address in a anti block tag: http://mitiay4.nar(remove)od.ru/fx603p_e.htm
Very strange site - but it has a description on how to make a cassete interface for the FX-603P with 3 electorinc components. Cool! There are also some Survey Calculation Programs programms.
An USB-Interface for the Casio FX-850P/FX-880P - which uses the same Interface connectior as the FX-603P. The Interface itself work fine with the FX-603P and can be used with MS-Windows and Mac OS X based PC's.